1. Field of the invention
This invention relates to encoding an identification of a receiving unit associated with a television, radio or other receiver, or terminal coupled to an information distribution network, to enable the receiver or terminal to select desired data from a generally broadcast stream of information and/or programming. This form of receiver or terminal may include a data processor incorporated in a receiver for showing audio and/or video information, or may be a separate unit, the typical application being a separate set top interface unit which is coupled between the source of a television broadcast signal (e.g., via cable) and a television for displaying the video and audio information on a selected channel.
2. Prior Art
In the past, a set-top unit was rendered distinct from other set-top units coupled to a distribution network, if it was distinct at all, by a unique serial number ("unique ID"), such as discussed for example in U.S. Pat. No. 5,070,404--Bullock et al, by assignment of a unique frequency or other dedicated channel means, as discussed for example in U.S. Pat. No. 4,450,477--Lovett, or by another aspect which allows the set-top unit to process information directed to it and to ignore information directed to other set-top units on the distribution network. Alternatively, the set-top unit could be provided with decryption means which was lacking in other units, thereby distinguishing at least a subset of set-top units such as subscribers to a premium cable channel or the like. This uniqueness of the set-top unit allowed for services such as pay-for-play, subscription services, and digital information subscriptions to be directed by unique ID, frequency, and the like to the paying subscribers, while other subscribers who declined such services could remain coupled to the network but could not process the respective signal.
However, if services need to distributed according to a class of subscribers other than those addressed by their unique identifiers, channels or hardware, it is not readily possible to distinguish among the set-top units such that some can decode the broadcast and others ignore it. For example, there is no way to use pre-ordained distinctions of this type as a means to direct broadcast messages to classes of subscribers based on selected locations, unless the locations are cross referenced to the unique identifier or the like, which is cumbersome. For information services, video messages and various other uses, it would be desirable to allow a user of a set-top unit to filter information from the service based upon proximity of the user to the service, or based on the user's selection of a location which may be or may include an area remote from the unit, which otherwise is of interest to the user. Examples of other locations of interest could include, for example, a place of business, a travel destination or route, the location of a loved one, or other location.
The present invention provides a means for identifying a television receiver or the like based on location, and also for encoding other location information, whereby generally broadcast messages or programming can be filtered and processed by only the users having an interest in the information due to proximity. In this respect, the encoding of information applies both to location specific digital information contained in the broadcast, and location selection information which is preferably input to the system by the user, including but not limited to the location of the receiver itself.
Transmission of digital information over existing carriers as a supplement to conventional broadcasting has been available for many years. Examples are such systems as TeleText and closed captioning. These systems all use custom decoders to make a limited amount of specific information available to users having a custom decoder. The information is broadcast to all receivers, but only the subscribers can use it. Typically the amount of data transmitted is limited by the fact that the digital information is embedded in a single channel with the general broadcast. For example, TeleText and closed captioning are typically encoded during the vertical retrace period of the video signal. A single line of text characters, or at most a screen of text characters, are stored and displayed.
Alternative methods for limiting access to information and/or the ability to process the information include the use of entitlement messages (e.g., U.S. Pat. No. 4,868,866--Williams), unique message identification (U.S. Pat. No. 4,829,372--McCalley), frequency multiplexing (U.S. Pat. Nos. 4,677,686--Hustig and 4,450,477--Lovett), and encryption (U.S. Pat. No. 4,323,921--Guillou). Although these devices permit selection of a subset of users who can use a generally broadcast message, their application to filtering information based upon arbitrary locations or ranges of locations are limited due to the need to define locations and to convert such information into the very different methods by which the users are rendered distinct from one another.
Limitations of the prior art techniques for distinguishing users with respect to selected locations or proximities are inherent in the type of distinguishing techniques used. For example, when entitlement messages are used, an entitlement message for every receiver must be transmitted at least once before the message, thus requiring considerable bandwidth to enable receipt of public safety and information broadcasts which are to be sent to a large group of users. Unique message identification requires transmission of multiple copies of the same information, each copy possessing a unique ID or addressing code for decoding by one user. Frequency multiplexing requires modulation and broadcast of information on multiple channel frequencies, which is useful for distinguishing relatively large groups but cannot be applied practically to distinguish users down to useful differences in location, even assuming that local multiplexing and frequency conversion equipment is provided to accomplish the encoding. Encryption also requires either broadcasting multiple copies of the same information encrypted with the various keys possessed by the receivers, or addressed broadcasting of new encryption keys to individual users every time a different subset of users is to be selected. Moreover, known location distinctions are limited to the location of the receiver and are inapplicable to arbitrary ranges of proximity, selection via a plurality of geographic locations and/or areas of interest, and the like, which would enable generally broadcast information to be filtered for geographically pertinent information.
It is known to attempt to activate receivers in the event of an emergency broadcast (e.g., U.S. Pat. No. 3,993,955--Belcher). However, such systems provide no selectivity based upon the location of the receiver, which is activated in a general broadcast mode. It is also known to attempt to limit processing of information to particular subscribers having a certain zip code or state code (e.g., U.S. Pat. No. 5,070,404--Bullock et al). However, these invariable geographic definitions lack the versatility of arbitrarily defined areas, and the specificity of more localized location identifications that could render an information distribution system useful for local commercial offers and the like.
Providing for selective broadcast using any of the methods of frequency multiplexing, encryption, message identification and the like, requires that the broadcaster maintain a catalog of all of the relevant receiver frequencies, encryption codes, or unique IDs. This catalog is limited to the location of the receiver. An inaccurate catalog can result in customer dissatisfaction with respect to general services at a minimum. When public safety information is broadcast, omission of customers can result in personal injury, property loss, or even fatalities. In addition to social responsibility issues, the broadcaster who attempts to define a subset of specific users at risk may provide a false sense of security. On the other hand, a set-top unit that can determine its own location (by a variety of methods) or can respond to a designation of arbitrary locations, immediately and accurately receives the geographically targeted information which the user requires.
According to the present invention, a processor is coupled between a receiver operable to display, record or play back information, and monitors digital information encoding location identifiers in a general broadcast signal. This arrangement allows the generally broadcast information to be filtered for locations in a variety of ways, and these ways preferably are embodied in applications routines to which users have access. There is currently no system capable of selectively providing user services based on user definable geographic locations in the manner discussed herein.